A number of micro-organisms have been shown to produce 3-hydroxypropionic acid (3HP) (Andreeken, B. and Steinbuchel, A., Applied and Environmental Microbiology (2010), 76, 4919-4925). The synthesis of 3HP and other related hydroxylated carboxylic acids and polyalkanoates generally occurs under growth limiting culture conditions (Brigham C. J. et al., S3 Microbiol and Biochemical Technology (2011)). Production of hydroxyl carboxylic acids and their polymeric forms, and in particular 3HP, are of commercial significance. 3HP (CAS No. 503-66-2) can be converted to acrylic acid (CAS No. 79-10-7) on dehydration and as such is a useful platform molecule.
Previous reports of the synthesis of commercially useful amides using micro-organisms generally refer to the hydrolysis of nitriles by bacteria such as Rhodococcus or Pseudomonas species employing a nitrilase/nitrile hydratase system. Such bacterial systems are used to good effect for the synthesis of acrylamide from acrylonitrile in industrial processes (Mitsubishi process). However, de novo synthesis of acrylamide, acrylonitrile or the precursor molecule 3HP amide by a micro-organism has not been previously reported.
Two green routes to the synthesis of acrylonitrile have been reported, namely the synthesis from glycerol (V. Calvino-Casilda et al., Green Chemistry (2009), 11, 939-941) and synthesis from glutamic acid (J. Le Notre et al., Green Chemistry (2011), 13, 807-809). Synthesis from glycerol requires chemical amination, and while it represents green chemistry it is not de novo synthesis of the molecule or a precursor. The availability of glycerol from biofuel operations may be limiting and represents an issue in the debate about “food for fuel”. Also synthesis from glutamic acid, which is produced by fermentation from by-products of sugar process such as vinasse (from sugar beet), may represent a larger carbon foot print than the petrochemical equivalent and be of no advantage.
WO 2013/011292 and WO 2015/118341 describe a micro-organism which is capable of producing long-chain aliphatic carboxylic acids and esters of 3-hydroxypropionic acid. These documents relate to a particular strain referred to as Acetobacter lovaniensis FJ1 having accession number NCIMB 41808 (deposited at NCIMB Ltd. (Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen, AB21 9YA) on 12 Jan. 2011 under the provisions of the Budapest Treaty).